120 Healy Review Essay A Wealth of Notions Kieran Healy1 Freakonomics: A Rogue Economist Explores the Hidden Side of Everything. William Morrow, 2005. Steven Levitt and Stephen Dubner. I will admit that I rolled my eyes. Behold the Freakonomist! ‘‘Politically incorrect in the best, most essential way,’’ the blurb said. The work of an allegedly ‘‘rogue economist,’’ who goes out of his way in the first few pages to say he is ‘‘afraid of calculus’’ and does not know how to do the- ory. Amazing! Incidentally, this particular rogue trained at Harvard and MIT, was at the Harvard Society of Fellows, won the John Bates Clark medal and teaches at the University of Chicago. Moreover, since the book’s publication in 2005, Freakonomics has become an enormous best- seller, enjoying widespread media coverage, a widely-linked website, and a regular column in the New York Times. All of which makes Steven Levitt an interesting kind of maverick. If only my own fear of calculus had pro- pelled me towards the same peripheries. But there is little point in carping. Steven Levitt does very high-quality work that is reliably provocative, almost always in a productive sort of way. The packaging of the book—the silly title, the effort to distance the contents from the everyday work of the dismal science, the song-and-dance to make Levitt himself seem a little, well, freakish—is mostly the result of getting a journalist and a marketing department on board. It may also be a consequence of turn- ing out the goods a little too fast. The book itself is a bit thin. Yet the underlying material matters both because it is substantively interesting and because it exemplifies a kind of applied economics that is becoming increasingly prevalent. Levitt is less freak and more foreshadow, an exam- ple of what the future may hold not just for the practice of economics, but for social science more generally. Sociologists should pay attention to the substance of what he is doing, and then ask whether we think we have something better to offer in response. 1University of Arizona; e-mail: [email protected]. A Wealth of Notions 121 Bearing in mind that each step is much easier to say than to do, Levitt’s standard operating procedure is as follows: (1) Find an interesting puzzle, (2) Get hold of a relevant dataset, the bigger the better, (3) (This is the crucial step) Come up with a really clever instrumental variable, measurement technique, natural experiment, or other methodological move that extracts evidence from the data in a surprising and compelling way, and (4) Voila! You can now demonstrate some elegant, usually counterintuitive, social mechanism. The book gives a tour of Levitt’s many successes in applying his enormous talent for this kind of work. The substantive topics range from the whimsically neat to the seriously pro- vocative. On the one hand, we have cheating in Sumo wrestling tourna- ments or patterns of free-riding on a bagel delivery service. On the other hand, there are estimates of the long-term effects of Roe vs. Wade on crime rates (via abortion rates), the economics of drug-dealing, or the effects of gun control legislation or sentencing policy on crime rates. Levitt’s knack for finding striking answers to tricky problems using recal- citrant data is remarkable. The first thing to notice is that none of these research questions is unique to economics. In this respect, Levitt’s protests that he is not a regular economist are more than just marketing talk. As Freakonomics moves from topic to topic, it is clear that empirical puzzles about social action interest Levitt much more than a desire to elaborate or extend the theoretical framework that characterizes modern economics. Now, what makes for a distinctively economic approach is itself a contentious prob- lem. There are several answers available from within the discipline itself, and economists tend to go back and forth between them as the circum- stances demand. Often, they like to think of themselves as the hard- headed realists of the social sciences. On this view, social life is about rational agents selfishly and unremittingly pursuing their goals under con- ditions of scarcity. Thus, economics is about building rigorous models that capture these facts of life. The contrast is with woolly headed humanists and bleeding-heart sociologists, who allegedly prefer altruism over self- interest, and social norms or culture to individual rationality. At other times, though, economists play the role of hand-wringing rationalists. In this interpretation, individuals frequently fall short of the rational ideal. They follow some rule of thumb rather than work out the probabilities when they make decisions. They fail to take advantage of others when the opportunity arises, even when there is no cost to themselves. They tip at restaurants they will never visit again. Thus, economics is prescriptive rather than descriptive. It tells us how we ought to act or would act if only we were clever enough to think straight. And at yet other times, economists claim an instrumentalist middle-way. They freely acknowledge 122 Healy that their models make unrealistic assumptions—what science worth its salt does not?—but argue that as long as people in the aggregate act as if they were rational utility maximizers, then economics is the best game in town. For its advocates, this is an ideal position, a way to have your the- oretical cake and eat it. Critics charge this makes it impossible to reject the null hypothesis in research: If people do not seem to be acting in a rationally self-interested way, you are obviously not looking hard enough. Where does Freakonomics stand? On the face of it, it is in the realist camp: What this book is about is stripping a layer or two from the surface of modern life and seeing what is happening underneath … Incentives are the cornerstone of modern life … Economics is, at root, the study of incentives: How people get what they want, or need, especially when other people want or need the same thing (12). Unless you already know what an incentive is, however, it is hard to make any sense of this definition. Although the book does a good job conveying the findings of Levitt’s research, its treatment of important concepts and methods is breezy, even allowing for the fact that its goal is to reach a big audience. Initially, the book’s story is straightforward: People respond rationally to incentives, and the data reflect this if you look at them the right way. Levitt’s research on the commissions earned by realtors is like this. He is able to show that realtors generally sell other people’s homes for less money than they sell their own (and for how much less). This is because the extra commission they stand to make from getting a house to sell for $310,000 instead of $300,000 is too small to make the extra time and effort worth their while. Elsewhere, the detective work is even more impressive. Careful analysis of data on patterns of responses to multiple-choice quizzes administered to third-graders is used to demonstrate that teachers cheated on behalf of their students in order to improve average performances on mandatory tests. Here the trick is using the data to reveal a perverse incent- ive at work. But in many other cases, it is very tricky to figure out where the incentives really are, what form they take, or what the game being played actually is. In patterns of baby-naming, for instance, the incentives are less clear and the precise nature of the process is difficult to specify. (This topic has also been investigated by sociologists, a point I return to below.) As Levitt’s empirical concerns broaden, the notion of incentives is forced to do more and more work. Incentives can be financial, social, murky, moral, perverse, hidden, planned, misplaced, other-directed, and so on. Like the ‘‘positive reinforcement’’ of behaviorist psychology or the ‘‘functional imperatives’’ of 1960s sociology, ‘‘incentives’’ threatens to become an all-purpose placeholder having a specific meaning in each par- ticular case, but without adding up to a distinctive, unified explanatory A Wealth of Notions 123 concept. The danger is that we will always be able to explain things in terms of incentives, as long as we are prepared to make the concept of incentives broad enough to include whatever it is that gives people reason to act in the situation under study. A reader who just wants to learn about the many neat findings does not have to worry about the way the theme of ‘‘It is all incentives’’ is twis- ted this way and that, or care that it begins to fray under the stress. But there are implications for the kind of economics that Levitt is doing. At the very beginning of Freakonomics, we get a glimpse of the book as it might have been: We did consider, for about 6 minutes, writing a book that would revolve around a single theme—the theory and practice of applied microeconomics anyone?—but opted instead for a sort of treasure-hunt approach (14). A book called Explorations in Data-Driven Econometric Methods for Plausibly Inferring Causal Mechanisms in Many Social Contexts prob- ably would not have gotten very far either. But that is essentially what Freakonomics is. Most of the distinctive themes and theories of economics are absent from it, most notably the preoccupation with efficient markets and the commitment to the rationality of individuals, narrowly conceived. Instead, statistical methods are center stage.